data_global
_amcsd_formula_title 'SiC-IV'
loop_
_publ_author_name
'Ramsdell L S'
_journal_name_full 'American Mineralogist'
_journal_volume 29
_journal_year 1944
_journal_page_first 431
_journal_page_last 442
_publ_section_title
;
 The crystal structure of alpha-SiC, type IV
;
_database_code_amcsd 31
_chemical_formula_sum 'Si7 C7'
_cell_length_a 3.073
_cell_length_b 3.073
_cell_length_c 52.78
_cell_angle_alpha 90.0
_cell_angle_beta 90.0
_cell_angle_gamma 120.0
_cell_volume 431.643
_exptl_crystal_density_diffrn  3.239
_symmetry_space_group_name_H-M 'R 3 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'x,x-y,z'
  '2/3+x,1/3+x-y,1/3+z'
  '1/3+x,2/3+x-y,2/3+z'
  '-y,-x,z'
  '2/3-y,1/3-x,1/3+z'
  '1/3-y,2/3-x,2/3+z'
  '-x+y,y,z'
  '2/3-x+y,1/3+y,1/3+z'
  '1/3-x+y,2/3+y,2/3+z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.0  0.0  0.0
Si   0.0  0.0  0.191
Si   0.0  0.0  0.286
Si   0.0  0.0  0.429
Si   0.0  0.0  0.571
Si   0.0  0.0  0.714
Si   0.0  0.0  0.81
C   0.0  0.0  0.036
C   0.0  0.0  0.226
C   0.0  0.0  0.321
C   0.0  0.0  0.464
C   0.0  0.0  0.607
C   0.0  0.0  0.75
C   0.0  0.0  0.845